U.S. patent application number 13/237019 was filed with the patent office on 2012-04-05 for non-transitory computer-readable medium storing design check program, design check apparatus, and design check method.
This patent application is currently assigned to FUJITSU LIMITED. Invention is credited to Yoshiaki Hiratsuka, Kenji Nagase, Keisuke Nakamura, Tomoyuki Nakao, Yoshihiro Sawada.
Application Number | 20120084034 13/237019 |
Document ID | / |
Family ID | 45890540 |
Filed Date | 2012-04-05 |
United States Patent
Application |
20120084034 |
Kind Code |
A1 |
Hiratsuka; Yoshiaki ; et
al. |
April 5, 2012 |
NON-TRANSITORY COMPUTER-READABLE MEDIUM STORING DESIGN CHECK
PROGRAM, DESIGN CHECK APPARATUS, AND DESIGN CHECK METHOD
Abstract
A design check method executed by a computer includes
determining a countermeasure component provided in a certain range
from a terminal of a reference component, determining whether a
terminal of the determined countermeasure component is electrically
connected to the terminal of the reference component, and
determining that the countermeasure component is suitably mounted
when the terminal of the determined countermeasure component that
is electrically connected to the terminal of the reference
component is at least within the certain range.
Inventors: |
Hiratsuka; Yoshiaki;
(Kawasaki, JP) ; Sawada; Yoshihiro; (Kawasaki,
JP) ; Nagase; Kenji; (Kawasaki, JP) ; Nakao;
Tomoyuki; (Kawasaki, JP) ; Nakamura; Keisuke;
(Kawasaki, JP) |
Assignee: |
FUJITSU LIMITED
Kawasaki
JP
|
Family ID: |
45890540 |
Appl. No.: |
13/237019 |
Filed: |
September 20, 2011 |
Current U.S.
Class: |
702/65 |
Current CPC
Class: |
G06F 30/367 20200101;
G06F 30/398 20200101; G06F 2119/10 20200101; H05K 3/0005 20130101;
H05K 1/023 20130101 |
Class at
Publication: |
702/65 |
International
Class: |
G06F 19/00 20110101
G06F019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 30, 2010 |
JP |
2010-220207 |
Claims
1. A non-transitory computer-readable medium storing a design check
program, which when executed by a computer, causes the computer to
execute an operation, comprising: determining, based on design
data, a countermeasure component provided in a certain range from a
terminal of a reference component; determining, based on the design
data, whether a terminal of the determined countermeasure component
is electrically connected to the terminal of the reference
component; and determining that the countermeasure component is
suitably mounted when the terminal of the determined countermeasure
component that is electrically connected to the terminal of the
reference component is at least within the certain range.
2. The non-transitory computer-readable medium according to claim
1, which causes the computer to execute: referring to a storage
unit storing a net connected to the terminal of the reference
component and a class of the countermeasure component of the net,
the net and the class being associated with each other, and
determining that the countermeasure component is suitably mounted
when the class of the countermeasure component which is
electrically connected to the terminal of the reference component
is stored in the storage unit as the class of the countermeasure
component of the net connected to the terminal of the reference
component.
3. The non-transitory computer-readable medium according to claim
1, wherein the determining of whether the terminal of the
determined countermeasure component is electrically connected to
the terminal of the reference component includes: determining that
the terminal of the determined countermeasure component is
electrically connected to the terminal of the reference component
when the terminal of the determined countermeasure component and
the terminal of the reference component are connected to a same
net.
4. The non-transitory computer-readable medium according to claim
1, which causes the computer to execute: calculating, based on the
design data, a distance measured along a form of a net connecting
the terminal of the reference component and the terminal of the
determined countermeasure component, and determining that the
countermeasure component is suitably mounted when a value of the
distance is within a threshold set for each net.
5. A design check apparatus, comprising: means for determining,
based on design data, a countermeasure component provided in a
certain range from a terminal of a reference component; means for
determining, based on the design data, whether a terminal of the
determined countermeasure component is electrically connected to
the terminal of the reference component; and means for determining
that the countermeasure component is suitably mounted when the
terminal of the determined countermeasure component that is
electrically connected to the terminal of the reference component
is at least within the certain range.
6. A design check method executed by a computer, comprising:
determining, based on design data, a countermeasure component
provided in a certain range from a terminal of a reference
component; determining, based on the design data, whether a
terminal of the determined countermeasure component is electrically
connected to the terminal of the reference component; and
determining that the countermeasure component is suitably mounted
when the terminal of the determined countermeasure component that
is electrically connected to the terminal of the reference
component is at least within the certain range.
7. A method of checking a design, comprising: extracting design
data of a countermeasure component within a predetermined range
from a terminal of a reference component; and verifying a
connection of a terminal of the countermeasure component extracted
using at least the predetermined range.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority of the prior Japanese Patent Application No. 2010-220207,
filed on Sep. 30, 2010, the entire contents of which are
incorporated herein by reference.
FIELD
[0002] The embodiments discussed herein are related to a
non-transitory computer-readable medium storing a design check
program, a design check apparatus, and a design check method.
BACKGROUND
[0003] In recent years, electro-magnetic interference (EMI) is
checked based on design data prepared by computer-aided design
(CAD). Japanese Laid-open Patent Publication No. 2006-155379
discusses a technology of executing a design check to suppress
electromagnetic wave noise occurring in IT products or the
like.
[0004] Mounting EMI-countermeasure components is one of the
countermeasures to reduce EMI. Information about EMI-countermeasure
components is disclosed by, for example, manufacturers of the
EMI-countermeasure components. Designers determine what kind of
EMI-countermeasure component should be selected for each net and
determine the position of the EMI-countermeasure component, etc.
based on the disclosed information about the EMI-countermeasure
components.
[0005] FIG. 1 illustrates an exemplary check of EMI countermeasures
in CAD data. In FIG. 1, the check is performed by tracing a net 3
from the terminal of a reference component 1 to find an
EMI-countermeasure component 2. According to the check, whether or
not the EMI-countermeasure component 2 is provided in the net 3 is
confirmed, and then another EMI-countermeasure component is
searched for by tracing another net.
[0006] In order to conform to international standards of CISPR 22,
countermeasures are taken against EMI occurring during ordinary
operations. Precision devices or apparatuses have been increasingly
multifunctional, capable of high-frequency operations due to
improved performance, and light-weighted. Consequently, it is
difficult to use the casing of an apparatus as a shield against
EMI. Therefore, countermeasures to reduce EMI of an apparatus
should be considered at the time when designing a printed circuit
board.
[0007] However, since each net is searched, much time is consumed
on checking EMI countermeasures in CAD data, which is illustrated
in FIG. 1.
SUMMARY
[0008] According to an embodiment, a design check method executed
by a computer includes determining a countermeasure component
provided in a certain range from a terminal of a reference
component, determining whether a terminal of the determined
countermeasure component is electrically connected to the terminal
of the reference component, and determining that the countermeasure
component is suitably mounted when the terminal of the determined
countermeasure component that is electrically connected to the
terminal of the reference component is at least within the certain
range.
[0009] The objects and advantages of the invention will be realized
and attained by at least the features, elements, and combinations
particularly pointed out in the claims.
[0010] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory and are not restrictive of the invention, as
claimed.
[0011] Additional aspects and/or advantages will be set forth in
part in the description which follows and, in part, will be
apparent from the description, or may be learned by practice of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] These and/or other aspects and advantages will become
apparent and more readily appreciated from the following
description of the embodiments, taken in conjunction with the
accompanying drawings of which:
[0013] FIG. 1 illustrates an exemplary check of EMI countermeasures
in CAD data.
[0014] FIG. 2 illustrates a design check method according to an
embodiment.
[0015] FIG. 3 illustrates how to calculate a
countermeasure-component search range.
[0016] FIG. 4 illustrates a hardware configuration of a computer
executing an embodiment.
[0017] FIG. 5 illustrates a block configuration of a design check
apparatus according to an embodiment.
[0018] FIG. 6 illustrates a structure of a netlist table.
[0019] FIG. 7 illustrates a structure of a pin table.
[0020] FIG. 8 illustrates a structure of a via table.
[0021] FIG. 9 illustrates a structure of a component table.
[0022] FIG. 10 illustrates a structure of a
countermeasure-component library table.
[0023] FIG. 11 illustrates a process performed by a design check
apparatus.
[0024] FIG. 12 illustrates an image of a process in FIG. 11.
[0025] FIG. 13 illustrates a block configuration according to
another embodiment.
[0026] FIG. 14 illustrates an exemplary modification of a
countermeasure-component library table.
[0027] FIG. 15 illustrates other processing operations performed by
a design check apparatus.
DETAILED DESCRIPTION
[0028] Reference will now be made in detail to the embodiments,
examples of which are illustrated in the accompanying drawings,
wherein like reference numerals refer to the like elements
throughout. The embodiments are described below to explain the
present invention by referring to the figures.
[0029] FIG. 2 illustrates an image illustrating a design check
method according to an embodiment. FIG. 2 illustrates a component 1
provided as a reference (hereinafter referred to as the reference
component 1), a net 3 which is electrically connected to a pin
(PIN) 4 which is a terminal of the reference component 1, and
EMI-countermeasure components (hereinafter referred to as the
countermeasure components) 2A, 2B, 2C, 2D, 2E and 2G (2A to 2G)
that are mounted on the net 3.
[0030] A net provided at a position beyond the countermeasure
components 2A, and 2E to 2G with reference to the pin 4 is
different from the net 3. In the check of EMI countermeasures
conventionally performed in CAD data, the check was started from
the pin 4 of the reference component 1 and performed along the net
3 to search for the EMI countermeasure components 2A to 2G. In
other words, each of the countermeasure components 2A to 2G mounted
on the net 3 was checked in the past. Consequently, when the net 3
has a complicated structure, it is difficult to execute the check
of the EMI countermeasures in the CAD data, causing the man-hours
to increase (requiring much time).
[0031] Therefore, according to the design check method of an
embodiment, first, a countermeasure-component search range 5
centering on the pin 4 of the reference component 1 is searched for
countermeasure components that are included therein. In FIG. 2, the
countermeasure-component search range 5 is searched to thereby find
the countermeasure components 2A and 2B that are included therein,
for example.
[0032] Subsequently, according to the design check method of an
embodiment, when any of the found countermeasure components is
connected to the same net as the pin 4 of the reference component 1
is connected to, it is determined that the countermeasure component
is mounted at an appropriate position (the countermeasure component
is appropriately mounted). FIG. 2 illustrates that the net 3, to
which the pin 4 is connected, is connected to the countermeasure
components 2A and 2B, and therefore it is determined that the
countermeasure components 2A and 2B are mounted at appropriate
positions.
[0033] The process of searching the countermeasure-component search
range 5 centering on the pin 4 of the reference component 1 for the
countermeasure component included therein is a process of searching
for a countermeasure component within a certain linear distance
from the pin 4 of the reference component 1. The method of
calculating the countermeasure-component search range 5 is
described below in detail. According to the design check method of
an embodiment, the countermeasure-component search range 5 is
searched for the countermeasure components 2A and 2B that are
included therein. Consequently, the search range is narrowed down,
and all the countermeasure components 2A to 2G that are mounted on
the net 3 may not be necessarily checked.
[0034] FIG. 3 illustrates an image illustrating the method of
calculating a countermeasure-component search range. The distance
between a pin of the reference component 1 and a countermeasure
component 2 is usually calculated as below. First, a relationship
between a radiation noise and the countermeasure component 2 is
described.
[0035] The countermeasure component 2 is not mounted on a net N1
illustrated in FIG. 3. Although the countermeasure component 2 is
mounted on a net N2 illustrated in FIG. 3, there is a large
distance between a pin of the reference component 1 and the
countermeasure component 2. The countermeasure component 2 is
mounted on a net N3 illustrated in FIG. 3 considerably near a pin
of the reference component 1.
[0036] Since the countermeasure component 2 is not mounted on the
net N1 and the net N1 serves as a noise-radiating antenna, the
radiation noise of the net N1 is increased. After the
countermeasure component 2 is mounted on the net N2, the radiation
noise of the net N2 is decreased. However, since there is a large
distance between the reference component 1 and the countermeasure
component 2 provided on the net N2, and part of the net N2, the
part extending between the reference component 1 and the
countermeasure component 2, serves as a noise-radiation antenna,
the radiation noise of the net N2 is increased.
[0037] Accordingly, it is effective to mount the countermeasure
component 2 on the net N3 as near the pin of the reference
component 1 as possible. In FIG. 3, the radiation noise is
decreased in the order of the nets N1, N2, and N3.
[0038] The countermeasure-component search range 5 is determined in
consideration of a limitation imposed when the countermeasure
component 2 is actually mounted (e.g., a condition for
manufacturing a mounter), that is, has at least several millimeters
and a length which prevents the net from being the noise-radiation
antenna. Here, the length which prevents the net from being the
antenna is related to the frequency of radiation noise to be
suppressed. The frequency is stated in CISPR standards, which are
international regulations usually used.
[0039] Although conditions are varied among target apparatuses,
other frequencies may also be suppressed by calculating the
countermeasure-component search range 5 of currently available
information technology equipment (ITE) on one side of the range of
from 150 kHz to 6 GHz, where a wavelength 2 attained on the one
side is shorter than that attained on the other side. In an
embodiment, therefore, the frequency is exemplarily determined to
be 6 GHz to calculate the length of the countermeasure-component
search range 5. The speed of light is expressed as 3.times.10.sup.8
(m/s).
The wavelength .lamda. (m)=the light speed (m/s)/frequency (Hz)
(1)
[0040] The length which decreases the antenna efficiency should be
less than (1/4).lamda.. When the above-described conditions are
applied to Equation (1), the wavelength .lamda. (m) is expressed by
the equation such that 3.times.10.sup.8 (m/s)/6.times.10.sup.9
(Hz)=0.05 m. It is preferable that the distance where the
countermeasure component 2 is mounted be less than 0.0125 m=0.05
(m)/4, which leads to the conclusion that the
countermeasure-component search range 5 where the countermeasure
component 2 is mounted is several mm to less than 12.5 mm. Without
being limited to the above-described exemplary method, another
method may be used to calculate the countermeasure-component search
range 5. While specific examples of calculating a range, the
present invention is not limited to these calculations and may
calculate a range relative to condition(s) affecting performance of
an apparatus.
[0041] A non-transitory computer-readable medium storing a design
check program, a design check apparatus, and a design check method
of the embodiments are exemplarily provided, and a program stored
in a medium, an apparatus, and a method having different names may
be provided.
[0042] For example, the design check method of the embodiment may
be achieved by a function of CAD, or a tool including a viewer,
etc., which is different from CAD. The design check program of an
embodiment may be executed by a single personal computer or server
computer, or a plurality of personal computers or server computers
for distributed processing. Hereinafter, the personal computer and
the server computer are collectively referred to as PCs.
[0043] A PC executing the design check program of the embodiment
includes hardware configuration illustrated in FIG. 4, for example.
FIG. 4 illustrates a hardware configuration of an exemplary PC
10.
[0044] The PC 10 includes an input device 21, an output device 22,
a recording medium reader 23, an auxiliary storage device 24, a
main storage device 25, an arithmetic processing device 26, and an
interface device 27 that are connected to one another via a bus
29.
[0045] The input device 21 includes a keyboard, a mouse, etc., and
is used to input various signals. The output device 22 includes a
display device or the like, and is used to display various windows,
data, and so forth. The interface device 27 includes a modem, a LAN
card, etc., and is used to connect the PC 10 to a network.
[0046] The design check program stored in the medium of the
embodiment is at least part of various programs controlling the PC
10 illustrated in FIG. 4. The design check program is provided
through the distribution of a recording medium 28 or downloaded
from a network.
[0047] The recording medium 28 recording the design check program
includes various types of recording media. For example, the
recording medium 28 may be a CD-ROM, a flexible disk, a
magneto-optical disk, etc., in which information is recorded
optically, electrically, or magnetically. Further, the recording
medium 28 may be a semiconductor memory including a ROM, a flash
memory, etc., in which information is electrically recorded.
[0048] When the recording medium 28 storing the design check
program is set into the recording medium reader 23, the design
check program is installed from the recording medium 28 into the
auxiliary storage device 24 via the recording medium reader 23.
When being downloaded from a network, the design check program is
installed in the auxiliary storage device 24 via the interface
device 27. The auxiliary storage device 24 stores therein files,
data, etc., in addition to the installed design check program. When
starting the design check program, the main storage device 25 reads
the design check program from the auxiliary storage device 24 and
stores therein the design check program. The arithmetic processing
device 26 executes various types of processing that will be
described later based on the design check program stored in the
main storage device 25. The PC 10 executing the design check
program is an example of the design check apparatus.
[0049] For example, the PC 10 executes various types of processing
illustrated in FIG. 5 based on the design check program stored in
the main storage device 25. FIG. 5 illustrates a block
configuration of an exemplary design check apparatus according to
an embodiment.
[0050] The design check apparatus 30 includes a netlist extraction
unit 31, a pin-information extraction unit 32, a
countermeasure-component extraction unit 33, a
countermeasure-component suitability determination unit 34, a
display control unit 35, a netlist table 41, a pin table 42, a via
table 43, a component table 44, and a countermeasure-component
library table 45. Each of the blocks that are illustrated in FIG. 5
may be provided as software, or part of the blocks may be provided
as hardware.
[0051] The netlist extraction unit 31 extracts a target net from
the netlist table 41. The pin-information extraction unit 32
identifies a pin (driver) of the target net in the netlist table
41. The pin-information extraction unit 32 extracts the center
coordinates of the pin (driver) of the target net from the pin
table 42.
[0052] The countermeasure-component extraction unit 33 extracts
components that are mounted in a countermeasure-component search
range from the component table 44. The countermeasure-component
search range may be calculated as described above and stored in the
auxiliary storage device 24, for example. The
countermeasure-component extraction unit 33 extracts components
that are connected to the target net from the extracted components
that are mounted in the countermeasure-component search range.
Further, the countermeasure-component extraction unit 33 extracts
the countermeasure component from the extracted components that are
connected to the target net.
[0053] The countermeasure-component suitability determination unit
34 references the countermeasure-component library table 45 and
determines whether or not the extracted countermeasure component is
suitable in view of the class of the target net. The display
control unit 35 displays the processing result on the output device
22 or the like.
[0054] The netlist table 41 is a record unit to record therein a
netlist. The pin table 42 is a record unit to record therein pin
information. The via table 43 is a record unit to record therein
via information. The component table 44 is a record unit to record
therein component information. The countermeasure-component library
table 45 is a record unit to record therein the class of a suitable
countermeasure component for each net.
[0055] FIG. 6 illustrates a structure of an exemplary netlist
table. The netlist table 41 in FIG. 6 includes as items thereof
"net address", "net name", "structure (coordinates and line
width)", "layer information", "type", "class", and "connection
information". The item "type" in FIG. 6 indicates the form of a
net, which is expressed as a line, plane, etc. The item "class" in
FIG. 6 indicates the class of a signal flowing through a net.
[0056] FIG. 7 illustrates a structure of an exemplary pin table.
The pin table 42 in FIG. 7 includes as items thereof "pin address",
"structure (center coordinates)", and "layer information". FIG. 8
illustrates a structure of an exemplary via table. The via table 43
in FIG. 8 includes as items thereof "via address", "structure
(center coordinates and diameter)", and "layer information". FIG. 9
illustrates a structure of an exemplary component table. The
component table 44 in FIG. 9 includes as items thereof "component
address", "component name", "structure (center coordinates and
vertical/horizontal lengths)", "connection net", "layer
information", "class", "value", and "countermeasure-component
flag". The item "class" in FIG. 9 indicates a class of a component
such as an inductor, resistor, capacitor, etc. FIG. 10 illustrates
a structure of an exemplary countermeasure-component library table.
A countermeasure-component library table 45 in FIG. 10 includes as
items thereof "net name", and "countermeasure component
(class)".
[0057] FIG. 11 is an exemplary flowchart illustrating operations of
a process that is performed by the design check apparatus. When the
processing advances to operation S1, the netlist extraction unit 31
searches the netlist table 41 based on, for example, "net name" as
a key, and extracts the netlist of a target net. According to the
example of FIG. 6, the netlist extraction unit 31 searches the
netlist table 41 based on a net name "CLK1" as a key, and extracts
the netlist corresponding to a net address "1". When the processing
advances to operation S2, the pin-information extraction unit 32
refers to the netlist of the target net, which is extracted at
operation S1, and confirms the address number (pin address) of a
pin (driver) included in the connection information of the netlist.
According to the example of FIG. 6, the pin-information extraction
unit 32 confirms an address number "1" as pin address, the address
number "1" being included in the connection information of the
netlist corresponding to the net address "1".
[0058] When the processing advances to operation S3, the
pin-information extraction unit 32 acquires from the pin table 42
the pin information corresponding to the pin address confirmed at
operation S2, and extracts structure (center coordinates) included
in the acquired pin information. The structure (center coordinates)
extracted at operation S3 represents the center coordinates of the
countermeasure-component search range. According to the example of
FIG. 7, the pin-information extraction unit 32 extracts center
coordinates "P3000" corresponding to the pin address "1".
[0059] When the processing advances to operation S4, the
countermeasure-component extraction unit 33 extracts a component
mounted in the countermeasure-component search range from the
component table 44. More specifically, the countermeasure-component
extraction unit 33 acquires information about a component from the
component table 44, and extracts structure (center coordinates)
included in the acquired component information. The
countermeasure-component extraction unit 33 determines whether or
not the component is mounted in the countermeasure-component search
range based on the distance between the center coordinates of the
countermeasure-component search range and those of the component.
According to the example of FIG. 9, it is determined whether or not
a component is mounted in the countermeasure-component search range
based on the distance between the center coordinates "P3000" and
center coordinates "P1000", "P1001", and so forth that are included
in structure of the component information.
[0060] When there are components that are mounted in the
countermeasure-component search range, the countermeasure-component
extraction unit 33 advances to operation S5, and extracts a
component connected to the target net from the mounted components.
More specifically, the countermeasure-component extraction unit 33
extracts a component connected to the target net by searching for
connection net of the component information of a component that is
mounted in the countermeasure-component search range based on "net
address" of the target net extracted at operation S1 as a key.
Connection net of the component information includes the net
address of the net to which the component is connected.
[0061] According to the example of FIG. 9, the
countermeasure-component extraction unit 33 searches for connection
net of the component information of a component that is mounted in
the countermeasure-component search range based on the net address
"1" as a key, so that the component corresponding to a component
address "3", which is connected to the target net, is
extracted.
[0062] When there are components that are mounted in the
countermeasure-component search range and connected to the target
net, the countermeasure-component extraction unit 33 advances to
operation S6, and extracts the countermeasure components from the
components that are extracted at operation S5. More specifically,
the countermeasure-component extraction unit 33 determines whether
or not the components are the countermeasure components by
referring to the countermeasure-component flag included in the
component information. According to the example of FIG. 9, the
countermeasure-component flag corresponding to the component of the
component address "3" indicates "ON", the component is extracted as
the countermeasure component.
[0063] When there is a component that is mounted in the
countermeasure-component search range and connected to the target
net, the countermeasure-component suitability determination unit 34
advances to operation S7, and determines whether or not the
countermeasure component extracted at operation S6 is suitable.
More specifically, the countermeasure-component suitability
determination unit 34 refers to the countermeasure-component
library table 45, and when the class of the suitable countermeasure
component of the target net agrees with that included in the
component information of the countermeasure component extracted at
operation S6, the countermeasure-component suitability
determination unit 34 determines that the countermeasure component
extracted at operation S6 is a suitable countermeasure component.
According to the example of FIG. 10, the countermeasure-component
suitability determination unit 34 searches the
countermeasure-component library table 45 based on the net name
"CLK1" as a key. Since a class "Resistor" of a suitable
countermeasure component of the target net agrees with a class
"Resistor" of the component corresponding to the component address
"3", the countermeasure-component suitability determination unit 34
determines that the component is a suitable countermeasure
component. When the component is determined to be the suitable
countermeasure component at operation S7, the display control unit
35 advances to operation S8, and displays data indicating that the
countermeasure component is suitably mounted in the target net.
[0064] When it is determined that no component is mounted in the
countermeasure-component search range at operation S4, that no
component is connected to the target net at operation S5, that
there is no countermeasure component at operation S6, or that there
is no suitable countermeasure component at operation S7, the
display control unit 35 advances to operation S9 and executes an
error display.
[0065] The error display may include information about the class of
the countermeasure component suitable for the target net. Although
a flowchart of FIG. 11 illustrates an example where a normal
display or an error display is executed for each target net, the
normal display or the error display may be executed after a
plurality of nets is processed.
[0066] FIG. 12 illustrates an exemplary image of a process of the
flowchart of FIG. 11. The netlist extraction unit 31 searches the
netlist table 41 based on a net name "CLK1" as a key, and extracts
the netlist of a net address "1" as the netlist of the target
net.
[0067] The pin-information extraction unit 32 refers to the netlist
of the net address "1", and confirms an address number "1" of the
pin (driver) included in connection information. The
pin-information extraction unit 32 acquires pin information having
the address number "1" as a pin address from the pin table 42. The
pin-information extraction unit 32 refers to structure (center
coordinates) included in the acquired pin information, and extracts
center coordinates "P3000" which become the center coordinates of
the countermeasure-component search range 5.
[0068] The countermeasure-component extraction unit 33 extracts a
component "R1" mounted in the countermeasure-component search range
5 based on the distance between center coordinates "P3000" of the
countermeasure-component search range 5 and center coordinates
"P1002" of the component "R1" that is stored in the component table
44.
[0069] Since the net address "1" is included in connection net of
component information of the component "R1" mounted in the
countermeasure-component search range 5, the
countermeasure-component extraction unit 33 determines that the
component "R1" is connected to the target net.
[0070] The countermeasure-component extraction unit 33 determines
whether or not the component "R1" which is mounted in the
countermeasure-component search range 5 and connected to the target
net is the countermeasure component based on
countermeasure-component flag of component information of the
component "R1". According to the component information illustrated
in FIG. 9, the countermeasure-component flag corresponding to the
component "R1" indicates "ON", which indicates that the component
"R1" is the countermeasure component.
[0071] The countermeasure-component suitability determination unit
34 further refers to the countermeasure-component library table 45
and acquires a class "Resistor" of a countermeasure component
suitable for the target net based on the net name "CLK1" as a key.
Since the class "Resistor" of the component "R1" agrees with the
class "Resistor" of the countermeasure component suitable for the
target net, which is acquired from the countermeasure-component
library table 45, the countermeasure-component suitability
determination unit 34 determines that the component "R1" is the
suitable countermeasure component.
[0072] As described above, according to an embodiment, whether or
not the position and class of a countermeasure component are
suitable is automatically and correctly determined at a high speed
for each net which may need measures against EMI on a printed
circuit board. Accordingly, whether or not the countermeasure
component is suitably mounted is readily determined.
[0073] In an embodiment, whether or not a countermeasure component
is suitably mounted is determined by determining whether or not a
suitable countermeasure component is mounted in a
countermeasure-component search range. According to an embodiment,
whether or not the countermeasure component is suitably mounted is
determined more accurately by considering a distance between the
center coordinates (pin) of the countermeasure-component search
range and the countermeasure component measured along the net form,
in addition to considering the conditions of an embodiment. This
embodiment is only partly different from the above-described
embodiment, and therefore, the same part as that of the
above-described embodiment will not be described as
appropriate.
[0074] FIG. 13 illustrates a block configuration of another
exemplary design check apparatus 30A according to an embodiment.
The design check apparatus 30A illustrated in FIG. 13 includes a
distance determination unit 36 in addition to the units of the
design check apparatus 30 illustrated in FIG. 5. The distance
determination unit 36 calculates the distance between the center
coordinates of the countermeasure-component search range and the
countermeasure component measured along the net form, and
determines whether or not the value of the calculated distance is
within a threshold, which is set for each net. Each of the blocks
that are illustrated in FIG. 13 may be provided as software, or
part of the blocks may be provided as hardware.
[0075] The threshold is set for each net in a
countermeasure-component library table 45A illustrated in FIG. 14,
for example. FIG. 14 illustrates another exemplary structure of the
countermeasure-component library table 45 illustrated in FIG. 10.
In addition to the items of the countermeasure-component library
table 45, the countermeasure-component library table 45A
illustrated in FIG. 14 includes "threshold" as an item thereof. The
item "threshold" indicates the threshold of the distance. It is
preferable that the value of the distance between the center
coordinates of the countermeasure-component search range and the
countermeasure component measured along the net form be within the
threshold in the item.
[0076] FIG. 15 is another exemplary flowchart illustrating
operations of a process that is performed by the design check
apparatus. In addition to the processing of the flowchart of FIG.
11, the flowchart of FIG. 15 includes operations S11 and S12.
[0077] When it is determined that the countermeasure component is
suitable at operation S7 of FIG. 11, the distance determination
unit 36 advances to operation S11 and calculates the distance
between the pin (the center coordinates of the
countermeasure-component search range) and the countermeasure
component. More specifically, the distance determination unit 36
refers to the netlist table 41 and traces the connections so that
the distance between the center coordinates of the
countermeasure-component search range and the countermeasure
component measured along the net form is calculated.
[0078] When the processing advances to operation S12, the distance
determination unit 36 refers to the countermeasure-component
library table 45A of FIG. 14, and acquires the threshold of the
distance of the target net. The distance determination unit 36
determines whether or not the value of the distance calculated at
operation S11 is within the threshold, which is acquired from the
countermeasure-component library table 45A of FIG. 14.
[0079] When the value of the distance calculated at operation S11
is within the threshold, the threshold being acquired from the
countermeasure-component library table 45A of FIG. 14, the display
control unit 35 advances to operation S8 of FIG. 11. When the value
of the distance calculated at operation S11 is greater than the
threshold, the threshold being acquired from the
countermeasure-component library table 45A of FIG. 14, the display
control unit 35 advances to operation S9 of FIG. 11.
[0080] According to an embodiment, it is determined that the
countermeasure component is suitably mounted more accurately by
considering the distance between the center coordinates of the
countermeasure-component search range and the countermeasure
component measured along the net form, in addition to considering
the conditions of the above-described embodiment.
[0081] As mentioned above, the embodiments can be implemented in
computing hardware (computing apparatus) and/or software, such as
(in a non-limiting example) any computer that can store, retrieve,
process and/or output data and/or communicate with other computers.
The results produced can be displayed on a display of the computing
hardware. A program/software implementing the embodiments may be
recorded on computer-readable media comprising computer-readable
recording media. The program/software implementing the embodiments
may also be transmitted over transmission communication media.
Examples of the computer-readable recording media include a
magnetic recording apparatus, an optical disk, a magneto-optical
disk, and/or a semiconductor memory (for example, RAM, ROM, etc.).
Examples of the magnetic recording apparatus include a hard disk
device (HDD), a flexible disk (FD), and a magnetic tape (MT).
Examples of the optical disk include a DVD (Digital Versatile
Disc), a DVD-RAM, a CD-ROM (Compact Disc-Read Only Memory), and a
CD-R (Recordable)/RW. An example of communication media includes a
carrier-wave signal.
[0082] Further, according to an aspect of the embodiments, any
combinations of the described features, functions and/or operations
can be provided.
[0083] All examples and conditional language recited herein are
intended for pedagogical purposes to aid the reader in
understanding the principles of the invention and the concepts
contributed by the inventor to furthering the art, and are to be
construed as being without limitation to such specifically recited
examples and conditions. Although the embodiments of the present
inventions have been described in detail, it should be understood
that various changes, substitutions, and alterations could be made
hereto without departing from the spirit and scope of the
invention, the scope of which is defined in the claims and their
equivalents.
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